Filter, receiver, transmitter and transceiver

Embodiments of the present invention provide a filter, a receiver, a transmitter, and a transceiver. The filter includes a resonant cavity component, a microstrip filtering component, and two connecting pieces, where the resonant cavity component includes at least two resonant cavities connected in parallel, each resonant cavity is provided with a resonator and a tuning screw, the microstrip filtering component includes a dielectric substrate and a microstrip positioned on the dielectric substrate, one of the connecting pieces matches and connects one end of the microstrip to the resonator on one resonant cavity, the other connecting piece matches and connects the other end of the microstrip to the resonator on another resonant cavity, and impedance of the resonant cavity component is less than impedance of the microstrip filtering component.